There are 2 steps, first one is a short call with an external HR, introducing the position. They said that the interview will be conducted next week. However, I did not receive any notification until Thursday night, so I sent an FU email to the HR. 6 minutes later, I suddenly received an email and was scheduled for an interview with the company's team the day after. The HR said that there might be a case study. For the interview, there was supposedly 2 interviewers, but only 1 showed up. The questions were not as depth as I thought, there were no case studies, and it only lasted 15 minutes (30 minutes were scheduled). This was the most underwhelming interview that I had. It was rushed, not clear, and unsympathetic.